Development of Gold Phosphorus Supported Carbon Nanocomposites

Vishal J. Mayani,Suranjana V. Mayani,Sang Wook Kim 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.2

Metal–containing carbon nanocomposites have shown significance promise in the area of energy storage, heterogeneous catalysis and material science because of their morphology and combined properties. Phosphorus–doped carbon nanocomposites with gold nanoparticles were developed by applying a simple impregnation method and metal deposition technique. Gold–phosphorus supported carbon nanocomposites with two sized (25 and 170 nm) were prepared from economical petroleum pitch residue as the carbon source using an advanced silica template method. These nanocomposites will lead to the novel applications in the field of material science with the combined properties of gold, phosphorus and carbon. The newly prepared gold phosphorus supported carbon nanocomposites were fully characterized using a range of different physico– chemical techniques.

Development of Gold Phosphorus Supported Carbon Nanocomposites

Mayani, Vishal J.,Mayani, Suranjana V.,Kim, Sang Wook Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.2

Metal-containing carbon nanocomposites have shown significance promise in the area of energy storage, heterogeneous catalysis and material science because of their morphology and combined properties. Phosphorus-doped carbon nanocomposites with gold nanoparticles were developed by applying a simple impregnation method and metal deposition technique. Gold-phosphorus supported carbon nanocomposites with two sized (25 and 170 nm) were prepared from economical petroleum pitch residue as the carbon source using an advanced silica template method. These nanocomposites will lead to the novel applications in the field of material science with the combined properties of gold, phosphorus and carbon. The newly prepared gold phosphorus supported carbon nanocomposites were fully characterized using a range of different physico-chemical techniques.

Development of Palladium, Gold and Gold-Palladium Containing Metal-Carbon Nanoreactors: Hydrogen Adsorption

Mayani, Vishal J.,Mayani, Suranjana V.,Kim, Sang Wook Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.5

Metal-carbon nanoreactors (MCNRs) were prepared from a pristine carbon cage (CC) using a simple and efficient template method with nano silica ball (NSB), pyrolysis fuel oil (PFO) and transition metals, such as palladium and gold. Metal nanoparticles were embedded in approximately 25 and 170 nm sized, highly ordered carbon cages. The newly developed Pd, Au and Au-Pd doped carbon nanoreactors were characterized by microanalysis, $N_2$ adsorption-desorption isotherm, powder X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), transmission electron microscopy and inductively coupled plasma (ICP) analysis. The ordered MCNRs have exhibited dynamic hydrogen adsorption capability compared to the carbon cage.

Simple preparation of tungsten supported carbon nanoreactors for specific applications: Adsorption, catalysis and electrochemical activity

Mayani, Vishal J.,Mayani, Suranjana V.,Kim, Sang Wook Elsevier 2015 APPLIED SURFACE SCIENCE - Vol.345 No.-

<P><B>Abstract</B></P> <P>Porous carbon supported tungsten carbide nanoreactors, two sizes (∼25 and 170nm), were designed using economical petroleum pitch residue followed by tungsten (W) doping. X-ray diffractions showed both carbon tungsten composites (CTC-25 and CTC-170) contained tungsten subcarbide (W<SUB>2</SUB>C) and monocarbide (WC) as the major and minor crystalline phases, respectively. The present study provides a multiple perspective of carbon tungsten composites (CTCs) for methanol oxidation (as an electrode), adsorption (as an adsorbent) and degradation (as a solid catalyst) of methylene blue (MB). The operational electrodes were designed from both CTCs and used as a catalyst in an electrocatalysis process. The electrocatalysts exhibited high and stable catalytic performance (CTCE-25>CTCE-170) in methanol electro-oxidation. The newly synthesized W-doped carbon nanoreactors were used successfully as an adsorbent for MB and a heterogeneous catalyst for MB oxidation. Ordered CTC-25 and CTC-170 exhibited dynamic MB adsorption within 15min and complete oxidation of MB in 25–40min. A synergetic effect between tungsten carbide and the carbon cage framework was noted.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Tungsten carbon composites have shown great recognition in catalysis and electrochemistry. </LI> <LI> W-carbon composites are prepared by template replication and W-doping on carbon cage. </LI> <LI> Nanocomposites offer enormous assurance as adsorbent, electrode and heterogeneous catalyst. </LI> </UL> </P>

Development of Palladium, Gold and Gold-Palladium Containing Metal-Carbon Nanoreactors: Hydrogen Adsorption

Vishal J. Mayani,Suranjana V. Mayani,Sang Wook Kim 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.5

Metal-carbon nanoreactors (MCNRs) were prepared from a pristine carbon cage (CC) using a simple and efficient template method with nano silica ball (NSB), pyrolysis fuel oil (PFO) and transition metals, such as palladium and gold. Metal nanoparticles were embedded in approximately 25 and 170 nm sized, highly ordered carbon cages. The newly developed Pd, Au and Au–Pd doped carbon nanoreactors were characterized by microanalysis, N2 adsorption–desorption isotherm, powder X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), transmission electron microscopy and inductively coupled plasma (ICP) analysis. The ordered MCNRs have exhibited dynamic hydrogen adsorption capability compared to the carbon cage.

SBA-15 Supported Fe, Ni, Fe-Ni Bimetallic Catalysts for Wet Oxidation of Bisphenol-A

Mayani, Suranjana V.,Mayani, Vishal J.,Kim, Sang Wook Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.12

Bisphenol A is considered as pollutant, because it is toxic and hazardous to living organisms even at very low concentrations. Biological oxidation used for removing this organic from waste water is not suitable and consequently application of catalytic wet oxidation has been considered as one of the best options for treating bisphenol A. We have developed Fe/SBA-15, Ni/SBA-15 and Fe-Ni/SBA-15 as heterogeneous catalysts using the advanced impregnation method for oxidation of bisphenol A in water. The catalysts were characterized with physico-chemical characterization methods such as, powder X-ray diffraction (PXRD), FT-IR measurements, N2 adsorption-desorption isotherm, thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis. This work illustrates activity of the catalysts for heterogeneous catalytic degradation reaction revealed with excellent conversion and recyclability. The degradation products identified were not persistent pollutants. GC-MS analysis identified the products: 2,4-hexadienedioic acid, 2,4-pentadienic acid and isopropanol or acetic acid. The leachability study indicated that the catalysts release very little metals to water. Therefore, the possibility of water contamination through metal leaching was almost negligible.

Catalytic Oxidation of Phenol Analogues in Aqueous Medium Over Fe/SBA-15

Mayani, Suranjana V.,Mayani, Vishal J.,Kim, Sang-Wook Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.9

This study evaluated the use of iron-impregnated SBA-15 (Fe/SBA-15) as a catalyst for the oxidative degradation of persistent phenol analogues, such as 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2-nitrophenol (2-NP), 4-nitrophenol (4-NP) and 2,4,6-trichlorophenol (2,4,6-TCP) in water. The oxidation reactions were carried out with reaction time, concentration of the phenols, amount of the catalysts, reaction temperature, pH of the reaction mixture as the process variables with or without using hydrogen peroxide as the oxidizing agent. The conversion achieved with Fe/SBA-15 at 353 K for 2-CP, 4-CP, 2-NP, 4-NP, 2,4,6-TCP was 80.2, 71.2, 53.1, 62.8, 77.3% in 5h with a reactant to $H_2O_2$ mole ratio of 1:1, and 85.7, 65.8, 61.9, 63.7, 78.1% in the absence of $H_2O_2$, respectively. The reactions followed pseudo first order kinetics. The leachability study indicated that the catalyst released very little iron into water and therefore, the possibility of secondary pollution is negligible.

Preparation of multi metal–carbon nanoreactors for adsorption and catalysis

Mayani, Suranjana V.,Mayani, Vishal J.,Lee, Jun Young,Ko, Sung Hyun,Lee, Soo Keun,Kim, Sang Wook Springer-Verlag 2013 Adsorption Vol.19 No.2

SBA-15 Supported Fe, Ni, Fe-Ni Bimetallic Catalysts for Wet Oxidation of Bisphenol-A

Suranjana V. Mayani,Vishal J. Mayani,김상욱 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.12

Bisphenol A is considered as pollutant, because it is toxic and hazardous to living organisms even at very low concentrations. Biological oxidation used for removing this organic from waste water is not suitable and consequently application of catalytic wet oxidation has been considered as one of the best options for treating bisphenol A. We have developed Fe/SBA-15, Ni/SBA-15 and Fe-Ni/SBA-15 as heterogeneous catalysts using the advanced impregnation method for oxidation of bisphenol A in water. The catalysts were characterized with physico-chemical characterization methods such as, powder X-ray diffraction (PXRD), FT-IR measurements, N2 adsorption–desorption isotherm, thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectroscopy (ICPOES) analysis. This work illustrates activity of the catalysts for heterogeneous catalytic degradation reaction revealed with excellent conversion and recyclability. The degradation products identified were not persistent pollutants. GC-MS analysis identified the products: 2,4-hexadienedioic acid, 2,4-pentadienic acid and isopropanol or acetic acid. The leachability study indicated that the catalysts release very little metals to water. Therefore, the possibility of water contamination through metal leaching was almost negligible.

Catalytic Oxidation of Phenol Analogues in Aqueous Medium Over Fe/SBA-15

Suranjana V. Mayani,Vishal J. Mayani,김상욱 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.9

This study evaluated the use of iron-impregnated SBA-15 (Fe/SBA-15) as a catalyst for the oxidative degradation of persistent phenol analogues, such as 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2-nitrophenol (2-NP), 4-nitrophenol (4-NP) and 2,4,6-trichlorophenol (2,4,6-TCP) in water. The oxidation reactions were carried out with reaction time, concentration of the phenols, amount of the catalysts, reaction temperature, pH of the reaction mixture as the process variables with or without using hydrogen peroxide as the oxidizing agent. The conversion achieved with Fe/SBA-15 at 353 K for 2-CP, 4-CP, 2-NP, 4-NP, 2,4,6-TCP was 80.2, 71.2, 53.1, 62.8, 77.3% in 5h with a reactant to H2O2 mole ratio of 1:1, and 85.7, 65.8, 61.9, 63.7, 78.1% in the absence of H2O2, respectively. The reactions followed pseudo first order kinetics. The leachability study indicated that the catalyst released very little iron into water and therefore, the possibility of secondary pollution is negligible.